Improvement in draft apparatus for metallurgy and other furnaces



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Draft Apparatus fn-r Metallurgia and 0t`h`r l-"uilfnacas.,a

`745m(Lanzar. n! JWM UNITED STATES PATENT OFFICE.

GEORGE WINGATE, OF BOSTON, MASSACHUSETTS. 4

IMPROVEMENT IN DRAFT APPARATUS FOR METALLURGIC AND OTHER FU'R'NACETS.

Specification forming part of Letters Patent No. 144,585, dated November 11, 1873;

August 12, 1873.

To all whom it may concern:

Be it known that I, GEORGE WINGATE, of Boston, Massachusetts, have invented a Draft- Producing Apparatus, of which the following is a speciiication:

My invention relates to apparatus for exhausting-the air above a iire-place so as to create a draft therein, and consists of pipes and passages arranged as described hereafter, and heated so as to create or facilitate a ilow of air or gas, and thus produce an upward blast in the stack.

In the drawing, Figure l represents part of a stack of a furnace, with my draft apparatus applied thereto; Fig. 2, a sectional plan on the line l 2; and Fig. 3, a sectional plan on the line 3 4, Fig. l.

rThe hollow casting A, through which the steam-pipes B B pass, may represent the foundation of the chimney or stack, and directly above the same is an annular steamchamber, E, of a square sectional form in the present instance, the said steam-pipes communicating with the bottom of this chamber at opposite points, and being provided with suitable cocks. The steam-chamber rests upon and, is contained within a short cylindrical casing, G, between which and the said chamber intervenes the outer cylindrical casing H of the stack, which is surmounted by the cappiece F. An air-chamber, D, is formed between the casing H, the top of the steamchamber, and a short cylindrical casing I, the latter having a ilange, g, upon which rest a series of pipes, b, communicating with the air-chamber, and supporting at their upper ends a plate and nozzle, J between which and the cap F intervenes a narrow annular aperture, f. The air-pipes b are arranged so that the products of combustion, passing upward, shall be in direct contact with said pipes, and through the interior of the said pipes, as well as through the air-chamber D, extend a series of steam-tubes, e, communicating freely with the steam-chamber E at their lower ends, but closed at their upper ends, where they are steadied and prevented from vibrating by stays h. (See Fig. l, and inverted transverse application filed section, Fig. 2 on the line 1 2.) In the casing H, at the point where it forms the outer wall of the air-chamber D, are a series of openings, t', (see transverse section, Fig. 3, on the line 3 4, Fig. 1,) which are covered by an exterior annular casing, K,conf1ned between the upper edge of the casing G and a band, L, fitting around the casing H, the said exterior casing having an inlet, M, and being capable of rotating upon the casing H, so as to present the funnel-like inlet M to the wind, that the latter may blow directly therein and pass into the chamber D. Air, preferably under a slight pressure, is caused to enter the casing K, and, after circulating in the same, passes equally through all of the openings t' into the chamber D, whence it rises through the pipes b, it being heated by the steam and gases both in the said chamber and pipes, and consequently expanded, so that it escapes finally through the narrow annular passage f, between the cap F and nozzle J, under a very considerable degree of pressure,

and thus produces a partial vacuum in the y stack, which induces the required rapid upward movement of the smoke and gases through the central passage a, and thus serves as eiectually as the usual blast in promoting combustion, but without involving the usual expenditure of fuel.

If it be desired to introducethe air into the apparatus luider a strong pressure, a blower may be attached to the inlet-pipe.

It will be evident that steam alone, or the gases alone, or both together, as above described, might, in carrying out my invention,

be used for expanding and increasing the ve-y locity of the air.

I claim as my invention--` l. The combination, with a iue or stack, of a series of air tubes or passages communieating with the flue, and arranged substantially as described, so that the air therein is heated and passes as a blast into the stack.

2. A draft-producing apparatus in which air-pipes b, contained within the space through which heated products of combustion are caused to pass, are combined with steam ings 'i with the Yexterior annular easing K, whether the latter be fixed or movable.

' In testimony whereof, I have signed my name to this specification in the presence of two subscribing Witnesses.

GEORGE WINGATE. [Lis] Witnesses T. A. SHEDD, D. M. PAT'JJEN. 

